Drill



J. T. PHlPPS Oct. 16, 1934.

INV/ENTOR.

Jab/7 7." phbw QQZO J. T. IPHIPPS 1 977 0 5 Oct. 16, 1934.

DRILL ,2 Sheets-Sheet v2 Filed Nov. 15, 1932 INVENTOR. Jafi/a 73 640;:

. ATTORNEYS.

Patented Oct. 16, 1934 UNITED STATES PATENT orrrcs I This invention relates to a drill.

The object of the invention is to provide a drill of'the character described'specially designed fon'well drilling and having detachable blades with novel means for securing said blades against detachment from the head.

Another object of the invention is to provide the combination with a head, of detachable blades and novel means for not only securing the blades '10 firmly seated in the head during drilling operations but which will also prevent the blades from dropping out even should said securing means become broken.

Another object is to provide a drill having detachable blades so secured therein that they will not chatter during the operation of the drill.

' Another object is to provide a drill having detachable blades secured therein by means whereby the blades, when worn, may be readily re- ,20 moved and replaced with new blades.

' Another object is to provide, in a drill, a novel type of cuttingblade.

With the above and other objects in view this invention has particular relation to certain novel features of construction, arrangement'of parts and use an example of which is given in this specification and illustrated in the accompanying drawings, wherein: g

Figure 1 shows an edge view of the drill. Figure 2 represents a fragmentary vertical sectional view taken on the line 2-2 of Figure 3. Figure 3 shows a cross sectional View taken on the line 3-3 of Figure 1.

Figure 4 shows a perspective view showing the blade assembly.

Figure 5 shows a side view of a modified form of the drill. r r Figure 6 shows a perspective view of the head of said modified form; Figure 7 shows a fragmentary vertical sectional view taken on the line 7-7 of Figure 8.

Figure 8 shows across sectional view taken on the line'8-8 of Figure 5, and

. Figure 9 showsa perspective view of the blade assembly of this form. I

In the drawings the numeral 1 designates the drill head whose upper end may be reduced and threaded to receive the drill collar whereby the drill is-attached to a drill stem. Across the lower end of the blade there is a deep, downwardly fiared, slot 2.

There are the cutting blades 3, 3, which are, preferably, oppositely directed and have the sharp cutting edges 4, 4. These blades are formed integrally with a transverse, web-like shank 5 which is tapered upwardly to conform to the of and to fit snugly on the slot 2. p

The outer margins of the shank and blades are substantially straight and approximately parallel so as to maintain the gauge of the bore. 7 At itsopposite margins the shank 5 has the inwardly facing vertical shoulders 6, 6 on 0pposite sides of the shank and these shoulders-abut opposite sides of the head to prevent the lateral movement of the shank and blades relative to the head, and to give additional stock to the margins of the blade shank so that'said margins will not so quickly wear away.

Behind the respective blades 3, 3 the shank 5 has the concaved bores 7, 7 which terminate at their lower ends in the tapped holes 8, 8, and the axes of these holes and bores are inclined forwardly relative to the vertical axis of theshank. Aligned, and having a common axis with, the holes 8, and complementing the bores 7 are the bores 9 upwardly through said head. The upper ends of shape the bores 9 terminate at the transverse shoulders 10, on opposite sides of the head. These shoulders are disposed at approximately right angles to the axes of the corresponding bores 9 and are formedby; recessing the head, as at 11, on each side to provide spacefor the insertion of the bolts 12. The inner ends of these bolts are reduced and formed into the threaded pins 13. The bolts 12 are inserted through the bores 9, 7 and the pins 13 are screwed into the tapped holes 8 until the bolt heads 14 abut the corresponding shoulders 10 and the bolts are then further turned until the shank 5 is drawn tightly up into the slot, or mortise, 2. Cotter keys, as 15, may then be inserted through the heads 14 and these will engage the faces 16 formed by recessing the head, to prevent the bolts 12 from turning and unscrewing from the blade shank. Said bolts 12 are of somewhat less transverse diameter than that of the bores wherein they are located so that as'the blade shank wears and it becomes-necessary to tighten it up further in the mortise 2 the bolts will have sufiicient lateral play to permit this tightening up withoutbinding.

In the form-shown in Figures 5 to 9 inclusive the head 1 has the transverse, upwardly tapering slot, or mortise, 2 to receive the tapering shank 5' oftheblades 3, 3. The lower end of the head 1 also has the transverse mortise 17 cutacross said lower end diagonally with respect to the slot 2. This mortise preferably, has straight, approximately parallel sides and the shank 5 has the lateral wings 18, 18 joined integrally with the said shank 5 and which are arranged to seat in the mortise 17 when the shank 5 is seated in the slot 2. The upper ends of the wings, preferably, terminate beneath the upper end of the shanks 5'. The lower ends of the Wings 18 are formed into the forwardly curved blades l9, 19 which terminate in the cutting edges 20, 20. The inner sides of the blades 19 are of a general arcuate contour, as shown in Figures 5 and '7 to permit the free passage of the drilling fluid and the outer margins of the wings l8 and the blades 19 are substantially straight and parallel to maintain the gauge of the bore, and the upper outer corners of the shanks 5, 5 as well as of the wings 18 are beveled off so as not to hang on projections in coming out of the bore.

The blade assembly, as shown in Figure 9, is secured in the head 1 by the bolts 12, in the same manner as above described in connection with the Figures 1 and 2. When this blade assembly is secured in the head 1 the driving torque, in drilling, will be transmitted, in part, through the wings 18 thus relieving the blade shank 5' from a part of said driving torque, or strain and lessening the liability of the shank to become twisted off or broken and the wings 18, fitted closely in the mortise 17 will prevent the chattering of the blade assembly should the shank 5' become loose in the slot 2.

In case the bolts 12 should become subjected to the strain of the driving torque and be broken the break would occur at, or adjacent, the upper ends of the pins 13 where they are weakest, but even then the blade assembly could not drop out of the head and fall into the bore for the reason that the bolts 12 extend into the recesses 7 angularly with respect to the vertical and said blade assembly, upon its downward movement, will wedge against said bolts and be thereby locked and retained in the head.

The head of each form may have a large, axial bore 21 extending downwardly from the upper end thereof and this bore branches forming two passages 22, 22 as shown in Figures 1 and 3, or four passages, as 23, as shown in Figures 5, 6 and 8 which terminate at the lower ends of the respective heads in front of the corresponding blades to supply the drilling fluid to the blades in drilling.

It is contemplated that the blades will be formed of durable material and hard surfaced to withstand the wear to which they are subjected but when the blades are worn off they may be quickly and easily removed and a new blade assembly substituted therefor.

It is obvious that mechanical changes may be made without departing from the principle of the invention and the drawings and description merely disclose what is now considered to be a preferred form of the invention by way of illustration only, while the broad principle of the invention will be defined by the appended claims.

What I claim is:-

1. A drill comprising a head having a transverse, downwardly fiared mortise at its lower end, a blade assembly having a tapering shank fitted into said mortise, said head and shank having a bore arranged angularly relative to the axis of the head and terminating at its lower end in a tapped hole in the shank, a bolt in said bore whose lower end is threaded into said hole and whose upper end interlocks with the head.

2. A drill comprising a head having a mortise across its lower end, a boring member having a fiat shank which fits closely in said mortise, said head being recessed to form an external shoulder and being provided with a bore leading downwardly from said shoulder at an angle relative to the axis of the head and continuing diagonally on into and terminating in said shank, a bolt in said bore having means thereon which engages said shoulder and other means thereon which enages with said shank at the lower end of the bore, lateral wings on the shank, said head having a lower end mortise to receive said wings.

3. A drill comprising a head having transverse mortises arranged in angular relation and one of which is downwardly flared, a blade assembly having a shank which is tapered and fits closely in said flared mortise, wings on said shank which fit into the other mortise, said head having a bore diagonal with respect to the vertical axis of the head and which continues on in the same direction into said shank and terminates in a tapped hole in the shank arranged approximately longitudinal of the corresponding blade, a bolt in the bore whose lower end is threaded into said hole and means on the bolt which interlocks with the head.

4. A drill comprising a head having a transverse, downwardly flared mortise at its lower end, a blade assembly having a tapering shank fitted into said mortise, said head and shank having a bore which converges downwardly relative to one wall of the mortise and which terminates at its lower end in a tapped hole, a bolt in said bore between which and said wall of the mortise the l shank is arranged to wedge, and whose lower end is threaded into said hole and whose upper end interlocks with the head, the transverse diameter of the bore being greater than that of the bolt.

5. A drill comprising a head having transverse mortises arranged in angular relation and one of which is downwardly flared, a blade assembly having a shank which is tapered and fits closely in said flared mortise, wings on said shank which fit into the other mortise, said head having an approximately vertical bore which continues on into said shank diagonally with respect to said mortise and terminates in a tapped hole, in the shank, a bolt in the bore whose lower end is threaded into said hole, the transverse diameter of the bore being greater than that of the bolt, and means on the bolt which interlocks with the head.

6. A drill. comprising a head having a transverse vertically extending mortise in its lower 1- cnd, a blade assembly having a web like shank fitted into said mortise, said head having a bore diagonal with respect to the axis of the head and which continues on into said shank, a bolt in said bore whose lower end engages with the blade assembly and whose upper end is in engagement with the head, said bolt and one side or said mortise converging downwardly so that said shank upon downward movement thereof in the mortise, will wedge between said bolt and said converging side of the mortise whereby the blade assembly will be prevented from dropping from the head.

JOHN T. PHIPPS. 

